package edu.czjt.reggie.filter;

import com.alibaba.fastjson.JSON;
import edu.czjt.reggie.common.BaseContext;
import edu.czjt.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * 对指定路径进行用户登录状态检查。
 * Created by jinkun.tian on 2023/3/20
 */
@WebFilter(filterName = "loginCheckFilter", urlPatterns = "/*")
@Slf4j
public class LoginCheckFilter implements Filter {

    public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;

        //1、获取本次请求的URI
        String requestURI = request.getRequestURI();

        log.info("本次拦截到请求：{}", requestURI);

        //2、判断本次请求是否需要验证
        // 不需要验证的url
        String[] urls = new String[]{
                "/employee/login",
                "/employee/logout",
                "/doc.html",
                "/webjars/**",
                "/swagger-resources",
                "/v2/api-docs"
        };
        boolean check = check(urls, requestURI);

        //3、如果不需要处理，则直接放行
        if(check){
            log.info("本次请求{}不需要进行登录验证",requestURI);
            filterChain.doFilter(request,response);
            return;
        }

        //4-1、判断employee登录状态，如果已登录，则直接放行
        if (request.getSession().getAttribute("employee") != null) {
            log.info("用户已登录，用户id为：{}", request.getSession().getAttribute("employee"));

            Long empId = (Long) request.getSession().getAttribute("employee");
            BaseContext.setCurrentId(empId);

            filterChain.doFilter(request, response);
            return;
        }

        //4-2、判断user登录状态，如果已登录，则直接放行
        if(request.getSession().getAttribute("user") != null){
            log.info("用户已登录，用户id为：{}",request.getSession().getAttribute("user"));

            Long userId = (Long) request.getSession().getAttribute("user");
            BaseContext.setCurrentId(userId);

            filterChain.doFilter(request,response);
            return;
        }

        //5、如果未登录则返回未登录结果，通过输出流方式向客户端页面响应数据
        log.info("用户未登录");
        response.setCharacterEncoding("utf-8");
        // response.getWriter().write("用户未登录");
        response.getWriter().write(JSON.toJSONString(R.error("用户未登录")));
        return;
    }

    /**
     * 路径匹配，检查本次请求是否需要放行
     * @param urls
     * @param requestURI
     * @return
     */
    public boolean check(String[] urls,String requestURI){
        for (String url : urls) {
            boolean match = PATH_MATCHER.match(url, requestURI);
            if(match){
                return true;
            }
        }
        return false;
    }
}
